Remove material.css and bootstrap.css as silent dependencies

[walterbm]

Many Mortar components are currently relying on styling provided by material.css and bootstrap.css. Mortar components should not rely on any outside styling libraries.

Look at the classes that any Mortar components uses. If those are classes declared by material.css or bootstrap.css there is a risk that the component is relying on outside styling. Name-space the classes with mortar- and pull any missing styling into the Sass partial for the component.